package cdu.sl.filter;

import cdu.sl.utils.CurrentHolder;
import cdu.sl.utils.JwtUtils;
import io.jsonwebtoken.Claims;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.PutMapping;

import java.io.IOException;

/**
 * 令牌校验过滤器
 */
@WebFilter(urlPatterns = "/*")
public class TokenFilter implements Filter {

    private static final Logger log = LoggerFactory.getLogger(TokenFilter.class);

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        // 1.获取请求路径
        String requestURI = request.getRequestURI();

        // 2.判断是否有登录请求 , 如果路径当中包含/login , 说明这是登录操作 , 放行

        if (requestURI.contains("/login")) {
            log.info("登录请求 , 放行");
            filterChain.doFilter(request, response);
            return;
        }

        // 3.获取请求头中的token
        String token = request.getHeader("token");


        // 4.判断token是否存在 , 如果不存在 , 说明未登录 , 返回错误信息(响应401状态码)
        if (token == null || token.isEmpty()) {
            log.info("token为空,响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

        // 5.如果token存在 , 校验令牌 , 如果校验失败 -> 返回错误信息(响应401状态码)
        try {
            // Claims继承自Map
            Claims claims = JwtUtils.parseToken(token);
            Integer empId = Integer.valueOf(claims.get("id").toString());
            CurrentHolder.setCurrentId(empId);
            log.info("当前用户id为:{} , 已存入到ThreadLocal", empId);
        } catch (Exception e) {
            log.info("令牌非法,响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return;
        }

        // 6.校验通过 , 放行
        log.info("token校验通过,放行");
        filterChain.doFilter(request, response);

        // 7.删除ThreadLocal中的数据
        CurrentHolder.remove();

    }
}
